Payment method declined--cannot download things from the store

Hey, lets make this quick.

So I purchased this app, Vector, and I didn't have enough money on my Visa gift card (linked to my Apple ID) to pay for it. So, I have an unpaid balance that is preventing me from, for example, downloading free apps, music, updating my mac, etc.

I sent emails and stuff to Apple support but I would really prefer not to have to wait for a response. Is there any way to cancel the purchase and go on with my life?

Thanks for the help.